1. Field of the Invention
The present invention relates to a personal verification apparatus for performing personal verification using a human biometric feature such as a hand geometry or a fingerprint.
2. Description of the Related Art
When personal verification is performed, an identification card which verifies the person himself or an identification number which is known by only the person himself is used. When the identification card is used, however, the card may often be lost or stolen. Therefore, it is difficult to assure the safety of the card. When the identification number is used, the number may often be forgotten or illegally used by a third person. For this reason, it is difficult to verify the person himself safely and reliably.
In order to solve the above problems, a collation method to verify the person himself using a personal human biometric feature has been developed. For example, a method utilizing a fingerprint disclosed in Published Unexamined Japanese Patent Application No. 59-2184, or a method utilizing a hand geometry including data of, e.g., the length and width of the fingers disclosed in Published Unexamined Japanese Patent Application No. 61-122797 are known as the verification method using the human biometric feature.
When the fingerprint is utilized, however, in order to collate a fingerprint read by a reader with a fingerprint registered in a memory in advance, complicated two-dimensional processing must be performed.
When the hand geometry is utilized, data of the palm including the length and width of five fingers of a person must be read by a reader. For this reason, the reader having the same size as that of the palm is required, and the size of the reader is undesirably increased. In order to solve the above problem, a verification method to verify the person himself using the length between the joints of a finger has been considered. In this verification method, image data of a finger is read by a reader, and the read image data of the finger is converted into a binary signal by an A/D converter. The contour of the finger is obtained in accordance with the binary signal, and the positions of the joints can be obtained from this contour. The length between the obtained joint positions is collate with the length between the joints stored in a memory in advance by a collator to verify the person himself.
In the collation using only the length between joints, however, an amount of data required to perform collation is small. Therefore, it is difficult to improve the accuracy of the collation. In order to accurately detect the length between the joints, the position of the distal end of the finger must be accurately obtained. However, in order to accurately obtain the position of the distal end of the finger, a unit for detecting the distal end of the finger is required, and an arrangement of the entire apparatus becomes complicated.
Note that, in "FINGER COLLATION AND PATTERN IMAGE PROCESSING APPARATUS" (U.S. Ser. No. 07/364,167) filed by the same applicant on June 12, 1989, the following method is disclosed. That is, in this method, image data of one finger is added in a direction perpendicular to the longitudinal direction of the finger, feature data of the finger is generated, and the feature data is compared with feature data to be collated which is generated and stored in advance.